I've noticed this phenomenon for a long time now, and it's really starting to become an issue with some of my macro shots. When I left-click to zoom an image to 100%, it doesn't actually zoom to the full image resolution. See the attached comparison between FPV (top) at 100% and Photoshop (bottom) at 100%.

Axel, thanks for the reply. Unfortunately I experience this problem with JPEGs straight from the camera. I haven't thought to experiment with JPEGs from different sources. FPV tells me the image resolution is 3888px wide, however at 100%, there is very little image stretching beyond my 1680x1050 resolution monitor.

For Smart Image Resizing, I had changed the "Maximum memory usage per image" down to 12MB from 112MB. Originally I did this because at times I could feel the effect of scrolling through large folders of images and the hit it had on my available RAM. I assumed that FPV didn't need much more than the actual image size for memory allocation... apparently I was wrong!